Recently, in the field of displays such as televisions including liquid crystal panels, as an approach to achieve higher performance, 3D displays with which 3D images can be enjoyed have been developed. In such 3D displays, a stereoscopic image can be displayed by, for example, making the right eye of a viewer see an image for the right eye and making the left eye of the viewer see an image for the left eye.
Various 3D display methods for displaying 3D images can be used, and examples of the methods known as methods requiring no special eyeglasses include a lenticular lens method and a parallax barrier method.
As one of display methods for viewers to see 3D images with eyeglasses, a circularly polarized glasses method, for example, is known (see Patent Document 1, for example).
In a 3D display using the circularly polarized glasses method, a retardation material is generally arranged on a display element for forming an image of a liquid crystal panel and the like. In this retardation material, two types of retardation regions having different retardation characteristics are regularly arranged each in plurality to constitute a retardation material that is patterned. In the present specification, a retardation material thus patterned in which a plurality of retardation regions having different retardation characteristics is arranged is called a patterned retardation material hereinafter.
The patterned retardation material can be fabricated by optically patterning a retardation substance including a polymerizable liquid crystal as disclosed in Patent Document 2, for example. In the optical patterning of the retardation substance including a polymerizable liquid crystal, a photo-alignment technique known for forming an orientation material for a liquid crystal panel is used. More specifically, a coating made of a material having photo-alignment properties is provided on a substrate, and two types of polarized beams having different polarization directions are radiated on this coating. Thus, a photo-alignment film is obtained as an orientation material in which two types of liquid crystal alignment regions are formed and the directions of alignment control of liquid crystals in the regions are different. Onto this photo-alignment film, a retardation substance containing a polymerizable liquid crystal in a solution state is applied to perform alignment of the polymerizable liquid crystal. Subsequently, the polymerizable liquid crystal thus aligned is cured to form a patterned retardation material.
As materials having photo-alignment properties that can be used in orientation material formation using a photo-alignment technique for liquid crystal panels, an acrylic resin and a polyimide resin, for example, are known that have in a side chain thereof a photodimerizable moiety such as a cinnamoyl group and a chalcone group, for example. It is disclosed that these resins exhibit a property of controlling alignment of liquid crystals (hereinafter, also called liquid crystal alignment properties) by polarized UV irradiation (see Patent Document 3 to Patent Document 5). Instead of an acrylic resin and a polyimide resin, for example, that have in a side chain thereof a photodimerizable moiety such as a cinnamoyl group and a chalcone group, the use of a low molecular compound having such a photodimerizable moiety is known, which increases alignment sensitivity (Patent Document 6). Patent Document 6 discloses that a polymer produced by using a (meth)acrylamide compound that is substituted with a hydroxymethyl group or an alkoxymethyl group may be used as a cross-linking agent, but discloses no specific embodiment.